Each of a marine seismic streamer and seabed cable is an elongate cable-like structure, which can be several thousands of meters long. The streamer or cable includes arrays of acoustic sensors (e.g., hydrophones) and associated electronic equipment along the length of the streamer. The acoustic sensors are used to perform marine and seabed seismic surveying.
Typically, a number of streamers are towed by a sea vessel to perform a marine seismic survey, while a seabed cable is deployed from the sea vessel and laid on the sea floor. The streamers and seabed cables are deployed from the sea vessel, typically from the aft of the sea vessel. Each streamer or cable is unwound from a reel or spool for deployment into the water. As a streamer or cable is deployed, it is useful to determine which sections of the streamer or cable are in the body of water. Typically, this is accomplished by using RFID (radio frequency identifier) readers positioned on the aft deck to detect RFID tags on the sections that are being deployed.
An issue associated with using this mechanism to detect which sections of the streamer are in the water is that there is typically a lot of activity at the aft desk of a sea vessel. Such activity may damage the RFID reader, such as due to accidental impact of other equipment with the RFID reader.
Another issue associated with using an RFID reader to read tags on the streamer or cable is that the RFID reader has to be far enough away from the streamer/cable reel and other sections of the streamer or cable to ensure that the RFID reader only detects the section that is being deployed. Such a requirement places constraints on the building of an RFID deployment system.